Objective: To determine the effects of pre- and postoperative inspiratory muscle training on length of postoperative hospital stay and pulmonary function in patients undergoing cardiac surgery.
Design and methods: We conducted a systematic search using databases (MEDLINE, CINAHL, EMBASE, PEDro and the Cochrane) to find controlled trials evaluating the effects of pre- and postoperative inspiratory muscle training.
Results: Eight studies fulfilled the inclusion criteria. Four were about preoperative inspiratory muscle training (416 patients), three about postoperative inspiratory muscle training (115 patients) and one study about pre- and postoperative inspiratory muscle training (43 patients). Preoperative inspiratory muscle training resulted in improvement in: Reduction in length of postoperative hospital stay of -2 days (95% CI -3.4, -0.7, N = 302), inspiratory pressure of 16.7 cm H2O (95% CI 13.8, 19.5, N = 386), forced expiratory volume in one second of 3% predicted (95% CI 0.1, 6, N = 140), forced vital capacity of 4.6% predicted (95% CI 1.9, 7.4, N = 140). Patients that received preoperative training had an inspiratory muscle training reduced risk of postoperative pulmonary complications, (RR = 0.6; 95% CI 0.5 to 0.8; P = 0.0004, N = 386). Postoperative inspiratory muscle training resulted in improvement in inspiratory pressure of 16.5 cm H2O (95% CI 4.9, 27.8, N = 115), and tidal volume of 185 ml (95% CI 19.7, 349.8, N = 85).
Conclusion: Pre- and postoperative inspiratory muscle training showed to be a beneficial intervention in the treatment of patients undergoing cardiac surgery.
Keywords: Cardiac surgery; exercise; preoperative care; respiratory muscle training.